Automatic furnace stoker



Nov. 6, 1934.

V. M. CRUICKSHANK AUTOMATIC FURNACE STOKER Filed Oct. 5, 1931 2 Sheets-Sheet 1 D I I w.. 1 o

VENTOR I g sv I AT1LORNEY Nev, 6, 1934. v. M, CRUICKSHANK AUTOMATIC FURNACE STOKER 2 Sheets-Sheet 2 Filed Oct. 5, 1931 000 O 0 0 O 000 O 0000 0000 00 0 000 0 000 O 0000 0000 0000 000% o oooooooogod 0000000000 00 I lNVENTOR V11. firm; ziiaizanit ATTORNEY WITNESS Patented Nov. 6, 1934 1 res This invention relates to automatic stokers for furnaces.

An object of the invention is the provision of an endless member adapted to be progressively fed across a combustion plate at the fire-bed of a furnace with means for supplying the moving and endless stoker with fuel, the endless stoker being composed of a plurality of fixed sections connected with driving chains and intermediately disposed swingable sections, each swingable section being mounted on the trailing edge of the fixed sections, the swingable section being adapted to be folded upon the respective fixed section upon the return trip of the sections to the front end of the furnace.

Another object of the invention is the provision of an endless stoker having a portion at all times moving across the combustion plate at the fire-bedof a furnace the remaining portion being 20 movable beneath the combustion plate and through the ash-pit, the stoker being formed of a plurality of spaced sections fixed to driving chains and alternate sections swingably mounted on the trailing edges of the fixed sections, means being employed in association with the driving chains of the endless stoker for aiding in cooling said chains and for guiding the fuel along the entire path through the combustion area of the stoker.

This invention will be best understood from a consideration of the following detailed description,. in view of the accompanying drawings forming a part of the specification; nevertheless it is to be understood that the invention is not confined to the disclosure, being susceptible of such changes and modifications as define nomaterial departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 is a view in perspective of an endless stoker constructed in accordance with the prin- .ciples of my invention,

Figure 2 is a view in perspective, reduced in size, of a combustion plate, 45 Figure 3 isa longitudinal vertical section taken alongthe line 33 of Figure 1,

Figure 4 is a transverse vertical section taken along the line 44 of Figure 3,

Figure 5 isa fragmentary bottom plan view of the fixed and swingable sections of the endless stoker,

Figure 6 is a side view of an axle for an idler sprocket, and

Figure 7 is a vertical section of a driving mechanism for a driving sprocket.

the hopper are inclined for not only restricting the hopper with the fuel.

Referring more particularly to the drawings, 10 designates a side wall of a stoker frame and 11 designates an end wall. The remaining walls of the stoker frame of the furnace are removed in order to more clearly disclose the 6 endless stoker in its operative relation within the furnace.

Axles 12 are secured to the side walls 10 of the stoker frame adjacent the inner end of the frame by means of nuts (not shown) which draw a shoulder 12 tight upon the side wall of the stoker frame. Heads 12 retain sprockets 14 loosely on the axles 12.

A stub axle 13 is secured to each side wall 10 H by a nut 113. A washer 114 engaging a shoulder 115 on the axle spaces a gear 116 from a side wall. The gear is connected in any approved manner to a sprocket 15. A shoulder or collar 117 retains the sprocket 15 and gear 116 on the stub axle 13. A gear 118 meshes with each of the gears 116, and the gears 118 are driven by a shaft 119. Chains, generally designated by the numeral 16, are trained on the sprockets and driven by the sprockets 15. An electric motor may be employed for driving the shaft 119 or 89 any other suitable source. of power may be utilized for the purpose. It will be noted that the sprockets 14 and 15 are hexagonal in shape and are adapted to have their alternate faces engage between pairs of links 1'7 of the sprocket chains lfi. The pair of links 17 are joined together by alternate single links, as shown at 18.

Lugs 19 project from the alternate faces of the sprocket and engage between links of the pairs.

A hopper 20 is located at the outer end of the stoker and extends transversely of the same so that the fuel may be fed directly to the endless stoker, throughout the entire width of said stoker. It will be noted that the side walls of the lower open end 21 of the hopper but for aiding in directing the fuel along predetermined points at the forward end of the furnace. Any suitable means may be employed for supplying The endless stoker is made up of a plurality of spaced fixed sections 22 and alternate sectudinal edges of the plate and are formed integrally with said plate as are the flanges 30. Said plate, however, may be formed in sections. Flanges 31 are spaced from the end flanges and extend between the flanges 28 and 29 and are spaced from the inner faces of the plates to provide passages for air from pockets 32 and 33 and this air passes outwardly through the perforations in said plate and through the ignited fuel carried by the sections of the traveling grate. A pair of webs 34 extends between the side walls of the flanges 28 and 29 and are spaced from each other and from the plate 25 in order to permit air Which enters pockets 35 and 35 located between the webs 3.4 to pass through the space below the plate 25 of the section 22, as will be presently explained The webs 34 are located centrally of the fixed. sections 22. It will be noted that there are no perforations above the pockets 32-33 and 35- 36. This arrangement of perforations prevents dirt or other foreign matter from passing into the air chamber as will be presently explained.

Each swingable section 23 is provided with. depending flanges, side and end walls and spaced webs in substantially the same manner as are the sections 22 and a detailed description of the various elements composing the swingable section is omitted.

At the ends of the flanges or webs 26 and 29 are formed depending flanges and 41 which are spaced from each other and these flanges are perforated to receive pins 42. A link 43 is pivoted at one end on the pin 42 while the'opposite end of the link is pivoted upon a pin 44 carried bydepending flanges 45 and 46 which are formed integrally with a section 23. It will be noted that a pair of links 43 are provided adjacent the opposite end walls of a fixed section and a corresponding swingable section and these links are seated in pockets 4'7 and 48.

The free edges of the flanges and partitions which depend from the plates which compose the fixed and swingable sections of the endless stoker ride over the upper face of a combustion plate 50. An air chamber 54 is formed by the combustion plate, side walls 51, an end wall 52, and a bottom'wall 53, the end walls and side wall being formed integrally with the combustion plate. This air chamber is connected with asource of air and sufiicient pressure may be applied thereto to force the same into the air chamber 54 and upwardly through longitudinally spaced series of slots 55. The means for supplying the air is not shown.

The combustion plate has a pair of curved lugs 56 spaced from each other and projecting from the outer end of the plate for aiding in guiding the fixed and movable sections of the endless stoker onto the combustion plate 50. The inner end of the combustion plate has a downturned lip 57 for guiding and supporting the swingable sections as they move to a vertical plane at the end of their inward travel and as they leave the combustion plate, as shown in Fig. 3. The links 43 provide for the swinging of the sections 23 and permit the swingable sections to be folded in a neat, compact manner upon the fixed sections 22.

A swingable scraper 60 is hingedly mounted at 61 in a socket 62 which depends from the inclined portion of the bottom plate 53 of the air chamber 54. The free end 63 of'the member 60 is adapted to scrape over the top of the swingable sections 23 when said sections are moving on their return trip through the ash pit as shown in Fig. 3 for removing from said sections foreign matter which has been dumped from the sections.

It will be noted that the parallel series of longitudinally disposed slots 55 formed in the combustion plate 50 are disposed respectively beneath the path of the pockets 32--33 and 3536 so that air entering the chamber 54 will pass upwardly through the slots 55 and enter the pockets noted above from which the air is distributed to the remaining portions of the space beneath the top plate of each section. Since this space below the tops of the sections is confined by the flanges 28 and 29 and flanges 30 and 31, an air chamber will thus be formed and the air will be substantially distributed to the perforations in the top plate of each section and pass upwardly through the ignited fuel carried by said sections. Each of the fixed sections is provided at each end with a laterally projecting lug which is received by a corresponding slot in the single links 18 so that when the chains 16 are driven the fixed sections will be carried along over the combustion plate with the swingable sections following the trailing edges of said fixed sections.

Adjacent the side edges of the endless stoker and embracing the chains are heat-radiating elements 75. These elements are formed. of metal or refractory and consist of a plate '76, spaced depending flanges 77, and a centrally disposed flange 78. It will be noted that the outer flange '77 is in flat contact with the outer face of the side wall 10 while the lower edge of the inner flange 77 is located slightly above the moving sections of the endless stoker. A centrally disposed flange '78 is located adjacent the outer face of each moving chain 16. Some of the cool air which leaves the air chamber 54 through the slots 55 passes through the spaces between the flanges 77 and the centrally disposed flange 78, thereby providing a cool operating space for chains 16. The members also provide guides for the fuel and maintain said fuel on the stoker.

Each axle 13 is provided with an inward extension 120 which projects into the path of the swingable sections 23 for engaging and supporting said sections when said sections tend to swing freely on the links 43 during the upward movement of the said sections over the sprock- 1 ets 15. This arrangement provides for substantially a noiseless operation of the traveling stoker adjacent the axle since the sections are guided. rather than allowed to fall into position.

The operation of my device is as follows: The sprockets 15 are driven by the gears 118 and 116 and the shaft 119 at a predetermined rate of speed and this speed is designed to move the members of the endless stoker across the plate 50 in such a way that the fuel will be properly burned in passing through the furnace.

As the alternate or pivoted sections 23 of the endless stoker reach the inclined plate 57, the free end of the sections will be supported by said inclined plate and gradually be lowered until they fall into a vertical position. The falling of the sections causes depositing of the ashes at the bottom of the ash pit. It will also be noted from Figs. 1 and 3 that the pivoted sections 23 will neatly fold upon the fixed sections 22 with the tops of the hinged sections being located in the same horizontal plane on their return travel through the ash pit. The end flanges of the fixed sections 22 and swingable sections 23 will have their adjacent edges resting upon each other, thereby closing the sections against the accumulation of ashes. walls of the sections will form a buttress to engage the ashes and move them to the front end of the furnace where they may be carried away.

The flanges or Webs on the inner faces of the sections of the traveling grate moving over the face of the combustion plate force any dust or silt which finds its way through the perforations 25 in the sections and falls on the combustion plate along the combustion plate until said dust or silt is discharged therefrom at the inner end of the combustion plate. The air from the air chamber 54 passing through the ports 55 in the combustion plate forces the dust or silt away from the air chamber so that the air chamber is maintained at all times free of foreign matter.

Furthermore, the air ports 55 in the combustion plate are arranged beneath those portions of the sections of the traveling grate where there are no perforations 25 so that there is no direct line of passages between the fire-bed and air chamber to permit dust or silt to fall into said air chamber.

The free end of each swingable section has a groove 125 extending the entire length of said section which receives a corresponding lip 126 on an adjacent fixed section for aiding in sealing the sections against the loss of air.

The fixed sections 23 have laterally disposed flanges 123 and 129 engaging adjacent portions of the swingable sections for aiding in preventing the loss of air from the sections when pass ing over the air chamber 54.

A movable partition 130 is mounted in the air chamber 54 and is moved back and forth longitudinally of said chamber by rods 131 having manipulating handles 132 located exteriorly of the stoker frame.

By moving the partition back and forth the effective air space in chamber is lengthened or shortened since the air is admitted to the chamber at the outer end which is adjacent the sprockets 15. When the partition is moved towards the end wall 52 of the air chamber, the area of the combustion plate through which air is supplied to the sections of the traveling stoker is considerably reduced. When the partition ismoved in the opposite direction the area is accordingly increased. By this construction, the area of combustion is controlled. A chamber 54 is supplied with air from the pipe 201 which is connected with a blower 200 driven by a motor 203. An air inlet pipe for the blower is shown at 202.

I claim:

1. In a furnace, an endless stoker composed of fixed sections and alternately disposed sections swingably mounted on the fixed sections, the free end of each swingable section having a longitudinal groove, and the adjacent end of each fixed section having a lip normally seating within the groove.

2. In a furnace having an ash pit and a firebox, an endless stoker composed of fixed sections and alternately disposed sections swingably mounted on the fixed sections, and links pivotally connected with adjacent portions of the fixed and swingable sections, means for supporting the fixed and swingable sections traveling through the firebox, means at one end of the supporting means for causing the swingable sections to be folded upon the fixed sections just before the sections move through the ash The two aligned end.

pit, the underface of the fixed and swingable sections having depending members similarly disposed so that said members will align when the swingable sections are folded on the respective fixed sections.

3. In a furnace, an endless stoker composed of fixed sections and swingable sections, spaced flanges projecting from the inner faces of the sections, pins carried by the spaced flanges, and links pivotally mounted on the pins for swingably mounting the second-mentioned sections.

4. In a furnace, an endless Stoker composed of a plurality of sections, a combustion plate supporting the sections at the fire-bed and provided with longitudinally disposed rows of slots, each section having a perforated top plate, end and side webs depending from the top plate, the free edges of the webs being in contact with and movable over the combustion plate, webs carried by the sections spaced from the top plate and normally engaging the combustion plate, said webs being disposed adjacent the slots in the combustion plate so that air from the slots will pass through the spaces between the top plates and the webs and will be distributed to the perforations in the top plates.

5. In a furnace, an endless stoker composed of spaced endless chains, fixed sections disposed in spaced relation and connected to the chains, sections swingably mounted on the fixed sections, means for driving the chains, a combustion plate for supporting the fixed and swingable plates at the fire-bed of the furnace, and means adjacent the side edges of the combustion plate and associated with the chains for aiding in cooling said chains and for guiding the fuel along the endless stoker.

6. In a furnace, an endless Stoker composed of a plurality of spaced sections, endless chains, means for driving the chains, said sections being fixed to the chains, sections swingably mounted on the trailing edges of the fixed sections, a combustion plate located Within the confines of the endless stoker and supporting the sections in a horizontal position at the firebed of the furnace, means at one end of the combustion plate for causing the swingable sections to be folded upon the fixed sections when said sections are moving beneath the combustion plate, and means swingably mounted on the combustion plate to engage the tops of the swingable sections for removing matter therefrom.

'7. In a furnace, an endless stoker composed of fixed sections and alternately disposed swingable sections, a combustion plate for supporting the fixed and swingable sections in a horizontal plane above the ash pit of the furnace, an air chamber below the combustion plate, means for supplying the air chamber with air, the combustion plate being provided with perforations for allowing air to pass through the combustion plate to the fixed and swingable sections, flanges at the opposite ends of the side edges of the fixed sections and moving in close association with the adjacent side edges of the swingable sections when said sections are moving over the combustion plate for preventing the loss of air along the side edges of the sections.

8. In a furnace, an endless Stoker composed of sections and chains supporting the sections, pairs of spaced sprockets on which the chains are trained, a gear connected with each sprocket of a pair of the sprockets for driving said sprockets, a spur gear in mesh witheach of the first-mentioned gears, a shaft for driving the spur gears, stub axles for rotatable mounting the sprockets and the gears, alternate sections being swingably mounted from adjacent sections, the stub axles having projections for engaging and supporting the swingable sections when said sections move through a curved path adjacent the respective sprockets.

9. In a furnace, an endless stoker, composed of sections, a combustion plate for supporting the sections in a horizontal plane, the sections being provided with a plurality of perforations, certain portions of the sections being free of perforations, the combustion plate being provided with elongated air passages beneath the portions of the sections which are free of perforations, an air chamber, the combustion plate forming the top of the air chamber, means for supplying the chamber with air, and means for operating the endless stoker.

10. In a furnace, an endless stoker composed of a plurality of sections, means for operating the endless stoker, a combustion plate for supporting he endless stoker in a horizontal plane when said stoker moves through the combustion chamber, a housing depending from the combustion plate and cooperating with the plate to form an air chamber, means for supplying one end of the chamber with air, the

sections of the stoker being provided with air passages, the combustion plate being provided with longitudinal rows of air passages for supplying air from the air chamber to the perforations in the sections of the stoker, a partition disposed transversely of the air chamber and movable therein, and means for moving the partition longitudinally of the air chamber, said partition adapted to control the effective air space in said chamber for controlling the combustion of fuel on the movable stoker along the length of the effective air space in said chamber.

11. In a furnace having an ash pit and a firebox, a stoker comprising an endless traveling member having alternately disposed rigid and swingable fuel-supporting sections extending transversely of the member with each swingable section attached to the preceding rigid member, and means for supporting the swingable sections in horizontal planes when said sections are traveling through the firebox and ash pit, said supporting means terminating adjacent the ends of the traveling member, the swingable sections assuming a vertical position when unsupported, the underfaces of the sections having similarly positioned depending members adapted to be aligned with the swingable sections resting on the fixed section when said sections pass through the firebox.

VIRGINIUS M. CRUIKSHANK.

eemiimmz 0e cemec'iime Eaeem Ne. 1,979 871n Nevember 6, i934.

VERGINiUS M. CRUEKSHANK.

it is hereby ceytified that errer apeears in the abeve numbered patent etion as ieiiews: in the heading te the drawiegs, name 0? "V. M QRUZCKSHANK" read V. CRUEKSHANK; and

that the said Letters mie21t simuid be read with this correetion therein the; be same may eeniorm te the recerd ef the case in the fii6nt Gfiiee.

Signe and sealed this 13th day 0% August, A. D. 1935.

reqeiying cerre appi 1mm 0:

Leslie Frazer (Seal) Acting Qemmiesioeer oi Patents. 

